The present invention relates to a circuit for tape duplication in video tape recorder, particularly to a system which can reduce picture degradation occurring in the case of tape duplication, by recording directly the read signal from a tape on another tape without FM modulation or demodulation.
Generally, if the image signal recorded on a tape is picked-up at a head, and the amplified and FM modulated signal becomes a luminance signal through FM demodulation, and after the color signal of low band(625 KHz+500 KHz) is demodulated, and the luminance signal and color signal are summed to be a composite image signal as a reproduction method of VTR, then after this composite image signal is received, the luminance signal and the color signal are separated from the composite image signal, and the separated signals are recorded again on a tape through FM modulation and the low frequency modulation for the color signal, as a recording method for a VTR, but in the conventional case when duplicating the VTR tape, the duplication can be achieved through reproduction and recording steps so that picture degradation is caused.
That is, in case of the duplicate of a VTR tape, the FM modulated signal and the low band modulated color signal are recorded through the FM demodulation and modulation, so that the picture quality can be subjected to greater deterioration since picture degradation is caused as the duplicating operation is repeated.